Ellipsograph



(ModeL) H. T. HAZARD.

ELLIPSOGRAPH" No. 309,852. Patented Dec. 30, 1884.

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IJMTED STATES PATENT rrrcn.

HENRY T. HAZARD, OF LOS ANGELES, CALIFORNIA.

ELLIPSOGRAPH.

SPECIFICATION forming part of Letters Patent No. 309,852, dated December30, 1884.

Application filed April 10, 1884. (Modem T (tZZ whom it may concern.-

Be it known that I, HENRY T. HAZARD, a citizen of the United States,residing at Los Angeles, in the county of Los Angeles and State ofCalifornia, have invented a new and useful Improvement in Ellipsographs,of which the following is a specification.

My invention relates to that class of instruments used by draftsmen indrawing ellipses.

The object of my invention is to provide a simple, accurate, andconvenient instrument by means of which a perfect ellipse of any desiredsize and form may be drawn with a single sweep of the pen or pencil. Iaccomplish this by means of the device described herein, and illustratedin the accompanying drawings, in which Figure 1 is a view of myellipsograph as it appears while in operation. Fig. 2 is an elevation ofthe pen attachment viewed from the side next to the pen. Fig. 3 is areverse view of the same. Fig. 4 is a section of the same on line as m,Fig. 3. Fig. 5 is an elevation of the pencil attachment viewed from theside of the blade which presses against the pencil. Fig. 6 is a sectionof the same on the line y y. Fig. 7 is a side elevation of the sameattached to a pencil. Fig. 8 is an enlarged View of one of thedivider-points.

The principle embodied in the pen attachment is identical with thatemployed in the pencil attachment; but owing to the differentrequirements of the pen and pencil they differ somewhat in construction.

In the drawings the same letters of reference are used for the similarparts of both attachments.

Ais the blade, which is curved to correspond with the blade of the pen,and is pro- 0 vided at its upper extremity with a drum, Z,

to which one end of a cord or thread is attached by being passed througha hole, L, in the flange B and secured by a knot in the cord. The hole Lis countersunk, so that the knot 5 does not project from the face of theflange. A groove, G, extends along the blade from the drum to the pointof the blade, Where the walls of the groove unite at the top, leaving atubular opening, H, through which the cord 50 passes out at the point ofthe blade. A small projection, F, having an eye, I, through it, extendsinto the groove G a short distance from the point, to form an attachmentfor the other' end of the thread. The drum Z is mounted in a recess atthe top of the attachment, and projects slightly beyond the inner faceof the blade A, so that when it is attached to the pen the drumwill'bear upon the pen, and will thereby become frictiontight. At thetop of the attachment, as at D, there is provided a steady-pin, E, madeto enter a hole made for that purpose in the blade of the pen, therebysteadying the attachment on the pen. In lieu of this steady-pin, twopoints may project out of the attachment and pass on either side of thepen-blade, whereby the hole in the pen-blade may be dispensed with. Theblade has a hole, K, through which the adjusting-screw of the pen passesto secure the attachment to the pen. A 1011- gitudinal slot may besubstituted for the hole K, so that the attachment may be raised orlowered to adjust the point H, through which the cord passes, at theproper distance from the point of the pen, whereby the same attachmentis adapted to be used on different pens having different lengths ofblade. The outer flange, G, of the drum is milled, so that the drum maybe rotated by the thumb and finger.

The pencil attachment is the same as that above described, except thatthe blade is bent to correspond with the point of a pencil, and that,instead of the hole K and steady-pin E for its attachment, it isprovided with aband, II, which encircles the pencil, and is providedwith a set-screw, Q, toclamp the pencil in lace.

I believe the most desirable manner of securing the drum in its place isby making a threaded socket in it and fastening it to the blade byascrew, M, as shown in the drawings.

I adapt a pair of dividers to be used with this attachment by providingthem with points having a small annular groove, P, and a shoulder, V,near the point, which is shown enlarged in Fig. 8.

When it is desired to use the ellipsograph,

a knotted cord is passed from the outside of I00 the'drum through thehole L, thence along the groove and through the opening H in the pointof the blade, thence back through the opening H and through the eye I inthe pro jeetion F, where it is secured by tying aknot on the end of thecord. Thus the attachment is provided at its point with a looped cord,J, one end of which is attached to the blade, while the other isattached to a drum, upon which it may be wound by rotating the drum. Theadj Listing-screw N is then removed from the drawing-pen, and theattachment is placed upon the pen, allowing the point E to enter theholeprovided in the blade of the pen for that purpose. The screw N is thenpassed through the hole K, which coincides with the screw-holes in thepen, and screwed into its place in the pen. \Vhen the screw is tightenedto close the pen, the screw will clamp the attachment firmly to the pen,and the point E will prevent any lateral movement thereof. The loop .Iis now placed around the points of the dividers, which are then set inthe two foci-points of the ellipse. The pen is then placed at anydetermined point on the proposed boundary of the ellipse and the drumrotated until the thread is drawn tight. The pen, first being filledwith ink, is then swept around the points, keeping the cord taut andallowing it to run in the notches I 1?, care being taken to turn the penasitmoves around, so that at all points it will run parallel with itsblades. The tendency of the cord is to hold it in such a position; butif it be heldrigidly in the fingers it will drag at points and blur theline, the pen turning once around in drawing the ellipse.

Ordinarily the dividers are held by the left hand and the pen in theright, and as the pen makes the circuit the dividers may be inclinedaway from the pen, so as to be out of the way of the right hand. Thepoint of the blade A should extend verynearly to the point of the pen,and the notches I? I on the points of the dividers should extend asclose to the bottom of the shoulder Vas possible, so that the cord willlie close to the paper while the line is being drawn, as the liabilityoferror increases with the distance of the cord from the paper. Thepurpose of the shoulder 'V below the notch is to prevent theneedle-point from entering the paper too far and binding the cord.

The pencil attachment shown in Figs. 5, 6, and 7 is operated in themanner above described, with the exception that less care is required todraw a neat ellipse. An ellipse drawn by this instrument is practicallycorrect. If at any time the tension produced by the friction of the drumis not suflicient to prevent the thread from slipping, the thread may bedrawn out of the groove and clamped between the blade and the pen orpencil.

What I claim as new, and desire to secure by Letters Patent, is-

1. A11 ellipsograph consisting of a pen provided with a drum or windingdevice, a cord confined near the point of the pen and there allowed todiverge to form aloop, one end 01' said cord being immovably attached tothe pen and the other end attached to the winding device, and twostationary needles, around which the cord slips to guide the pen indrawing an ellipse.

2. In an ellipsographic attachment for a pen or pencil, a bladeperforated at one end to admit a loop of cord, and being provided withmeans for attaching one end of the cord permanently thereto, and havinga drum to which the other end of the cord may be attached, whereby thesize of the loop may be regulated by rotating the drum.

3. In an ellipsograph, a 'pair of dividers each of the legs of which hasan annular groove near its point, in combination with a drawing-penprovided with a winding device, and a pen-guiding cord attached at oneend to the pen and atthe other end to the winding device, substantiallyas shown, whereby it is made adjustable as to length.

4. I11 an ellipsograph, the attachn1entA,having a drum, Z, the cord J,needle-points P l, grooved as shown, and the dividers and drawing-pen,all being in combination, substantially as shown and described.

5. In an ellipsograph, the combination of two needles or points, a penor pencil provided with a drum or take-up device, anda cord attached tothe pen at one end and to the takeup at the other end, said cord beingmade to diverge and form a loop encircling the points, such cord beingconfined or clasped at the point of divergence, substantially as shown,whereby the size of the loop is made constant while the instrument isbeing used.

6. In combination with a pair of dividers having their legscireumferentially grooved close to their points, and thereby adapted tohold a pen-guiding cord close to the paper in drawing an ellipse, apen-guiding cord seated in said grooves, and a drawing-pen attached tosaid cord, substantially as described.

7 In an ellipsograph, the combination of the blade A, having attachedthereto the cordwinding drum Z and the pen guiding cord, with adrawing-pen and a pair of dividers the legs of which have an annulargroove, all substantially as described and shown.

8. In an ellipsograph, the combination of a pair of dividers, adrawing-pen, a drum-carrying blade adapted for attachment thereto andhaving aperforation near its point, and a cord passing through suchperforations and attached to said-drum and blade, respectively,substantially as set fortln 9. In an ellipsographic attachment for apenor pencil, a cord-winding drum extending beyond the line of the face ofthe blade of the attachment, so as to impinge against the pen or penciland produce friction when-the attachment is in place, whereby the drumis prevented from slipping and loosening the cord.

' 10. In an ellipsograph, a pen-guiding cord immovably attached at oneend to a pen or pencil, and movably attached at the other end IIO to awinding or take-up device carried by said device, and having a cordsecured to said takepen or pencil, whereby the cord may be adup device,the cord diverging from near the jnsted as to length. point of the penor pencil to form a loop to 11. In combination with a pen or pencilencircle two points or needles and guide the 15 5 having a hole orsocket, an ellipsographic atpen or pencil in drawing an ellipse,substantachnient therefor having a point or needle tially as described.projecting laterally therefrom and adapted to enter the hole in the penor pencil to steady HENRY T. HAZARDQ the attachment thereon. lVitnesses:1o 12. An ellipsographic attachment for apen Jns. R. TOWNSEND,

or pencil, provided with a winding or take-up G. N. EARL.

